Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
trung nhan » truong nhan, trung phan, trong nhan
trong chan » trong chuan, trong cham, trong can
hoc chieu » hoc thieu, ho chieu, hoc hien
cong thuc » cong tac
cong huu » cong chuc, duong huu, cong hung
toan cao » toan ban, toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc chieu xanh - thanh ((trung nhan) or (trong chan)) dung ((cong huu) OR (cong thuc)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chieu xanh - thanh ((trung nhan) OR (trong chan)) dung ((cong huu) OR (cong thuc)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chieu xanh - thanh ((trung nhan) or (trong chan)) dung ((cong huu) OR (cong thuc)) toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc chieu xanh - thanh ((trung nhan) or (trong chan)) dung ((cong huu) OR (cong thuc)) toan cao*.